The present invention relates to a method of switching a guide mode in a navigation system that initializes a route guide by a map guide mode or a route guide by an arrow guide mode, and executes route guidance for a vehicle while appropriately switching the guide modes.
A navigation system for providing travel guidance to a driver whereby the driver can smoothly reach a desired destination detects the position of the vehicle, and reads map data for the vicinity around the vehicle position from a map storage medium, such as a CD-ROM, DVD, etc. In the Map Guide Mode, the navigation system draws the map and the guide route on the display screen, and superimposes a vehicle position mark on a specific place on the map. As the present position of the vehicle changes according to the movement of the vehicle, the system moves the vehicle position mark along the guide route on the screen, or scrolls the map with the vehicle position mark fixed at a specific position, so that the driver can grasp at a glance the detailed map and the guide route around the vehicle position.
In the Arrow Guide Mode, a guide route and roads intersecting the guide route, etc., are displayed in a simplified manner; the travel direction at an intersection is displayed with an arrow; the distance to the intersection, the direction to the destination, and the distance to the destination, etc., are displayed; and, further, the travel direction at the intersection is guided by a voice instruction.
In addition to the above, the map display mode includes the Hybrid Guide Mode that combines the Map Guide Mode and the Arrow Guide Mode. In the Hybrid Guide Mode, route guidance is executed normally by the Map Guide Mode, and when the vehicle approaches an intersection, the system executes route guidance by the Arrow Guide Mode. After the vehicle passes the intersection, the system recovers the initialized Map Guide Mode to execute route guidance.
FIG. 14 illustrates a method of initializing a route guide, from among the Map Guide Mode/Arrow Guide Mode/Hybrid Guide Mode. Operating the menu key on the remote control unit, the navigation system displays the main menu on the display screen (refer to FIG. 14(a)), and the user selects the menu xe2x80x9cSetupxe2x80x9d from the main menu. Then, the navigation system displays the xe2x80x9cGuidance Setupxe2x80x9d menu for specifying the guide mode as shown in FIG. 14(b). Next, if the user selects the menu xe2x80x9cGuidancexe2x80x9d, the navigation system displays the menu xe2x80x9cHybridxe2x80x9d, xe2x80x9cArrowxe2x80x9d, and xe2x80x9cMapxe2x80x9d, and the user selects a desired mode for the route guide. Thus, the initialization is completed. After completing the initialization of a guide mode, an operation of the MP/RG key on the remote control unit will appropriately switch the display mode in a cyclic manner as Map Guide Modexe2x86x92Arrow Guide Mode, Arrow Guide Modexe2x86x92Map Guide Mode, as shown in FIG. 15. FIG. 15(a) illustrates a display screen for the Arrow Guide Mode, and FIG. 15(b) illustrates a display screen for the Map Guide Mode.
In a conventional navigation system, when the user switches the guide mode by pressing the MP/RG key in an attempt to view and check the map display for a different guide mode, the guide mode value that has been initialized by the Setup menu is overridden thereafter, and the mode is switched into another guide mode. For example, in the case of the Map Guide Mode having been initialized, if the user presses the MP/RG key near a point of intersection to switch the mode into the Arrow Guide Mode, the navigation system will be switched into the Arrow Guide Mode thereafter.
Accordingly, the user needs to press the MP/RG key once again in order to recover the original guide mode that the user has set for a preference. In other words, when the user switches the guide mode by pressing the MP/RG key in order to see the map display for a different guide mode, the conventional navigation system will not recover the original guide mode set up in the xe2x80x9cMapxe2x80x9d or xe2x80x9cArrowxe2x80x9d mode, which is a problem that makes operation of the system troublesome.
The present invention has been made in view of the above problem, and it is an object of the invention to provide a method of switching the guide mode such that, when the guide mode is switched by the MP/RG key from the initialized guide mode into another guide mode, the system automatically recovers the initialized guide mode when a predetermined condition occurs.
In the method of switching a guide mode in a navigation system according to the invention, when a user initializes a route guide by the Map Guide Mode or a route guide by the Arrow Guide Mode, and executes the route guide for a vehicle by switching the guide mode, the foregoing object can be accomplished by automatically recovering the initialized guide mode when the predetermined condition occurs while in a guide mode different from the initialized guide mode.
In the following cases (1)-(4), the predetermined condition is judged to exist. That is:
(1) in the case of the initialized guide mode being the Arrow Guide Mode,
(a) when the vehicle deviates from the guide route and thereafter returns to the guide route, or
(b) when the vehicle deviates from the guide route, and thereafter returns to the guide route, and the guide point of an intersection and the guide contents (right-turn, etc.) are different from those before deviating from the route,
the predetermined condition is judged to exist. In these cases, the system automatically switches the guide mode from the Map Guide Mode into the Arrow Guide Mode.
(2) in the case of the initialized guide mode being the Arrow Guide Mode, when the vehicle approaches the point of intersection, the predetermined condition is judged to exist. In this case, the system automatically switches the guide mode from the Map Guide Mode into the Arrow Guide Mode.
(3) in the case of the initialized guide mode being the Map Guide Mode,
(a) when the vehicle deviates from the guide route, or
(b) when the vehicle deviates from the guide route and thereafter returns to the guide route, and the guide point of an intersection and the guide contents (right-turn, etc.) are different from those before deviating from the route,
the predetermined condition is judged to exist.
In these cases, the system automatically switches the guide mode from the Arrow Guide Mode into the Map Guide Mode.
(4) in case of the initialized guide mode being the Map Guide Mode, when the vehicle passes the point of intersection, the predetermined condition is judged to exist. In this case, the system automatically switches the guide mode from the Arrow Guide Mode into the Map Guide Mode.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings.